Footnotes:(1) Data refer to members of a labor union or an employee association similar to a union.(2) Data refer to workers who are not members of unions but whose jobs are covered by a union or employee association contract, as well as to members of a labor union or an employee association similar to a union.(3) Not strictly comparable with data for prior years. For an explanation, see the Historical Comparability documentation provided at www.bls.gov/cps/eetech_methods.pdf.

NOTE: Data refer to the sole or principal job of full- and part-time workers. All self-employed workers are excluded, regardless of whether their businesses are incorporated.

SOURCE: Current Population Survey, U.S. Department of Labor, U.S. Bureau of Labor Statistics.